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Notidanodon brotzeni

 Faktiske data om fund 
Katalognummer:
730
Accessionsnummer:
DK 636 (8)
Samling:
Danekræsamlingen
Samler:
Statens Naturhistorisk Museum
Finder:
Alice Rasmussen, Henning Rasmussen og Leif Rasmussen
Bestemt af:
Jan Adolfssen
Lokalitet:
Stevns Klint
Stratigrafi:
Skrivekridtet
Periode:
Kridt [Sen Maastrichtien]
Type:
Sediment:

Billede

Foto ©: Jan Adolfssen


 Beskrivelse:   af  Jan Adolfssen 
An assemblage of chondrichthyan teeth collected from the White Chalk (Upper Maastrichtian) in Stevns Kridtbrud. As the teeth are presented for Danekræ evaluation as one lot, they will not be described in detail, as it has not been deemed necessarily. All shark teeth’s from the Danish white chalk most be considered as very rare, especially large specimens (>5mm)! All specimens mentioned below should be considered as worthy for Danekræ.

DK_636a
10276. The tooth is almost complete, only missing parts of the root. The specimen is assigned to the late cretaceous species Squalicorax pristodontus (Agassiz, 1843), a cosmopolitan crow shark species. Although not uncommon in the rest of the world, the presences of the species in the Danish chalk is important for the understanding the distribution of this species and for understanding the top predatory guild in the late Cretaceous Danish marine fauna.

11008. The tooth is lacking parts of its root and a cusplet, but still identifiable. The specimen is assigned to the species Paraorthacodus conicus (Davis, 1890) and together with the more complete specimen 11009 they are the first known specimens of this species in the white chalk. DK_636b
11005 and 11094. Two rare complete specimens of the genus Centrophoroides (aff. appendiculatus) (Agassiz, 1843). The presences of Dogfishes in the chalk of Denmark are important for understanding the evolution and of the distribution of Dogfishes in the late cretaceous. DK_636c
11016, 11018 and 11019. Three well preserved lateral teeth from the species Carcharias latus (Davis, 1890). DK_636d
DK_636e
11017. A single well preserved specimen of Carcharias gracilis (Davis, 1890).
10489 and 11014. Two specimens of the species Pseudocorax affinis (Agassiz, 1843), both got well preserved cusps, but correspondingly badly preserved roots. DK_636f
DK_636g
11001. A specimen partly embedded in chalk. The tooth is only partly preserved but still identifiable to the genus Squatina. Angle sharks are notoriously difficult to identify to species level, but still very important in for our understanding of the benthic shark fauna.
DK_636h
11059. One specimen still embedded in chalk. Though badly preserved the Notidanodon brotzeni (Siverson, 1995) is very rare indeed and very valuable for understanding of the distribution of Hexanchiformes in the Late Cretaceous.
DK_636j
10458. One partly preserved specimen of Sphenodus faxensis (Davis, 1890), although among the more common species in the Bryozoan Limestone (Danien) it is the first known occurrence in the chalk.
DK_636k
2017. One specimen partly embedded in chalk and only partly preserved. Main cusp and one pair of cusplets are preserved whereas the root is in a bad state of preservation. Although the specimen due to the lack of preservation probably never will be identified to species level, it might offer some scientific value as it is the only known large lower intermediate tooth (sensu Shimada, 2007) from an Odontaspididae from the chalk.
Conclusion: All of the above mentioned specimens are extremely rare finds in the chalk and has great value for understanding the shark fauna in the late cretaceous of Denmark. They shall soon be figured in the coming scientific paper, and as such should be declared Danekræ.

Reference:
Agassiz, L. 1833–1843 Recherches sur les poissons fossiles (5 Volumes).
Imprimerie de Patitpierre, Neuchâtel, 1420 pp.

Davis, J. W. 1890. On the fossil fish ofthe Cretaceous formations of Scandinavia.
Scientific Transactions of the Royal Dublin Society, 4, 363-434.

Shimada, K. 2007. Skeletal and dental anatomy of the lamniform shark Cretalamna appendiculata, from the Upper Cretaceous Niobrara Chalk of Kansas
Journal of Vertebrate Paleontology, 27(3), 584–602

Siverson, M. 1995. Revision of the Danian Cow Sharks, Sand Tiger Sharks, and Goblin Sharks (Hexanchidae, Odontaspididae, and Mitsukurinidae) from Southern Sweden.
Journal of Vertebrate Paleontology, 15(1), 1-12

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